OK - everything I said yesterday was just bunk. Forget all about it. I now have the definitive answer to what ended the Silver Age! It was the publication of T.H.U.N.D.E.R. Agents #20.
If the introduction of Barry Allen as the Flash didn't signal the return of the super-hero, the JLA's first appearance in Brave and the Bold #28 certainly did. We all know the story of how the Marvel Age was basically the result of a golf game during which Martin Goodman learned of the success of the JLA series. The Fantastic Four were not alone, however, as the 1960s saw attempts by just about every comic book publisher to jump back onto the superhero bandwagon.
The most interesting line of superheroes from a non-Big Two company was certainly the T.H.U.N.D.E.R. Agents from Tower Comics. With Wally Wood leading an all-star team of creators, this series (and its spin-offs) certainly stood out from the crowd. Aside from the top notch artwork, the series had quite a few things going for it, especially the tragic nature of its heroes: Menthor was killed and stayed dead, Lightning lost some lifespan each time he used his powers and Raven was drawn by Manny Stallman (I kid, personally I dig Manny's work). Unfortunately, there were also a few problems like spotty distribution and the 25 cent price tag.
By early 1967, the Tower line had shrunk considerably and secondary titles like Dynamo, NoMan, UNDERSEA Agent and Fight the Enemy were all gone, leaving only the flagship title and Tippy Teen, an Archie-clone - but 60s Archie clones is an entirely different can of worms. The T.H.U.N.D.E.R kept rolling along until issue #19, cover dated November, 1968 and then somehow an all-reprint #20 was published 12 months later, bringing the Silver Age to an end.
Other groups that didn't live to see the end of the decade include Archie Comics's Mighty Crusaders, Dell's Fab Four, Harvey's B-Man, Spy Man et al., ACG's Nemesis and Magicman as well as Charlton's line of Action Heroes. The T.H.U.N.D.E.R Agents were the last line of 2nd tier super heroes, and with their demise fell the curtain of the superhero revival that was the Silver Age.
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